Stability of embankments founded on soft soil improved with lime/cement columns

A multi-column composite foundation is a benefit concept utilizing different column types with varying lengths and diameters to support the embankment fill and to mobilize the strength and stiffness of the soil at shallow depths. Stabilization of soft clayey soils with lime/cement columns has become a common ground improvement method in Europe, USA and Iran. This study presents the results of finite element analyses using the finite element software PLAXIS to investigate the consolidation behavior of a road embankment constructed on a multi-column composite foundation. Two-dimensional finite element software was used after the calibration of the model against a field case study and numerical analyses were conducted to investigate deformations of the widened embankments over soft soil with or without the remediation of foundation columns. The finite element results are calibrated for a period of 4 years. The settlement and differential settlement are presented and discussed in detail. Also, at the end of the paper, to improve the understanding of the behaviour of embankments on columns reinforced by geosynthetic sheet, a numerical study dealing with the transfer of load into the soil embankment was presented. Recommendations are made for the design of foundation columns to remedy roadway pavement failure due to widening of embankments.

Keywords:

embankment , soil treatment , PLAXIS , Foundation columns , Lime , Cement